There are few high-rise building sites in Gaza these days, but the
demand for cement is huge. Copying Hizbullah in Lebanon, Hamas is building
enormous underground installations - ammunition bunkers, tunnels, and
command posts.

Responding to intelligence reports, Deputy Defense Minister Matan Vilnai
has reduced the flow of cement from Israel to Gaza and is weighing a total
halt.

Security officials say Hamas is building tunnels beneath the centers of
major cities to enable freedom of movement for its forces should the IDF
enter.

In addition, outside the cities, Hamas is constructing tunnels beneath
the major entry roads into Gaza, to be filled with explosives and then
detonated beneath IDF convoys.

The underground construction also includes hundreds of Kassam and
Katyusha rocket launching positions that are protected from air attack.